Heat-treating apparatus



H. E. SOMES HEAT TREATING APPARATUS June 30, 1942.

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2 STxee'ts-Sheet 2 June 30, 1942. H. E. SOMES HEAT TREATING APPARATUSOriginal Filed June a, 1959 1 6 5 8 6 ,:-w .i W3 M 7 9 w L x 4% x 4 2 w4\1 n U w F iii: :21 i -iiiiiillr 4 v 2 I. 0 0 x 9 a 2 6 3 a j 1INVENTOR jfowardl, 5071265 ATTORNEY Patented June 30, 1942 U NlTEDLSTATES PATENT OFFICE 2,288,039 P near-rename APPARATUS Howard E. Somes,Detroit, vMich, assignor to Budd Induction Heating, Inc., Philadelphia,Pa., a corporation of Michigan Original application June 8, 1939, SerialNo.

277,996. Divided and this application September 22, 1941, Serial No.411,851

12 Claims. Y (on. 219-13) This application is a division of my copendinapplication Serial No. 277,996, filed June 8, 1939,

for Progressive heat-treating apparatus and method, now Patent No.2,281,333, dated April 28, 1942.

The present invention relates in general to induction heating and inparticular to means for the differential heat treatment of interiorportions of hollow objects, an important purpose being the hardening ortempering of such portions of objects of a material hardenable by heattreatment such as various ferrous alloys.

A primary object of the invention is the provision of an improvedapparatus for heat treating relatively long hollow cylindrical objects,such as cylinder sleeves for internal combustion engines, in incrementsprogressing continuously from end to end, and including an improvedinduction heat-treating head for use in an induction heat-treatingmachine, preferably a machine of the typeshown and described in mycopending application Serial No. 164,320, filed September 17, 193'7, forInduction heat-treating apparatus," now Patent No. 2,281,331, datedApril 28, 1942.

A more specific object is the provision of means whereby the localizedinternal heating of cylinders, such as mentioned above, to or beyond thehardening temperature may be accomplished with minimum clearance withoutdanger of contact between the heating head and the adjacent walls of theworkpiece, or danger oi. seizure of the heating. head by the work uponinward local expansion or upsetting of the inner wall portion of theworkpiece due to heating.

A further object is the provision of an improve provement in themechanical structure of induction heat-treating heads making possiblethe construction of heads of relatively small diameter withoutsacrificeof energy carrying capacity, strength and efficiency, andincluding efficient means for cooling the same.

While many features of the invention are essentiallyelectrical, certainothers are not limited in their application to electrical heating butare applicable to and advantageous with other kinds" of heating.

Various other objects and advantages of the invention will becomeapparent upon a perusal of the folowing specification and accompanyingthe same.

In the drawings:

Fig. 1 is an elevation of the induction heattreating head and mountingshaft therefor;

the drawings on a large scale of the induction heat-treating head per seand its connection with the mounting shaft;

Fig. 3 is a diagrammatic elevation, partly in section, showing theinduction heat-treating head, workpiece and quenching element incooperative relation.

Referring to the drawings in detail and first to Fig. 1, this shows acomplete, replaceable heating tool element comprising in general theinduction heat-treating head I0 carried by a hollow tool shaft H whichlatter and the insulated conductor sleeve I2 serve as electricalterminals for the heat-treating head. This assemblage of mounting shaftcarrying the conducting sleeve and heat-treating head constitutes aunitary tool element capable of use in a suitable machine assemblageproviding suitable means for efiecting relative sliding and rotationalmovement between the tool element and a workpiece with suitable slidingcontact means for supplying current to the heat-treating head throughthe concentric shaft and conducting sleeve, such as the machineassemblage shown and described in my aforesaid application. The toolelementis thus interchangeable with other tool elements varying in formaccording to the work to be done but subtsantially identical as to theform and proportions of the mounting shaft and conducting sleeve. Theheat-treating head [0 comprises an energizing or inducing coil orwinding l3 formed of a hollow tubular conductor having its terminalselectrically connected one to the tool shaft II and one to the insulatedconducting sleeve l2, and provided with a hollow cylindrical core ll ofmagnetic material having flange-like pole pieces I! and I6 extendingradially outwardly across the top and bottom ends of the coil. At thebottom of the bottom pole piece l6 substan tially at the outer edgethereof is formed an annular downwardly and outwardly directed spraynozzle opening I! in the form of a continuous annular slot for directingan annular spray. or jet of quenching fluid downwardly and outwardlyfrom the lower peripheral edge of the bottom pole piece. A second spraynozzle opening l8 also in the form of a continuous annular opening orslot is situated below the nozzle opening i1 and also has its outletportion directed downwardly and outwardly.

The heating head ID, as a whole, is slightly tapered downwardly so thatthe outside diameter of the lower core-flange or pole piece it, isslightly less than that of the upper pole piece of flange Fig. 2 is anelevation in vertical axial section 55 i5, their peripheral surfaces,preferably, being slightly tapered, forming continuations of a commonconical surface, so that the mean diameter of the outer peripheralsurface of the flange IE will be smaller than that of the flange iii.For example, in the present embodiment where the workpiece is an enginecylinder sleeve of 4% inches inside diameter, the diameter of the loweredge of the lower flange i6 is approximately '1 of an inch less thanthat of the upper edge of the top flange l5, the top flange having amean clearance suflicient to insure against actual contact with thework. It is this slight taper from top to bottom, that is, a slighttaper in a direction opposite to that of the direction of movement ofthe head relative to the workpiece during operation, which makespossible the use of a minimum clearance between the heat-treating headand the workpiece with assurance against contact head being threadedinto thev lower end of the supporting element I9 at 22. Mounted on theoutside of the shaft H is a conducting sleeve i2 insulated from theshaft by an intervening sleeve 23 of insulating material. At its lowerend the conducting sleeve i2 is flanged outwardly and abuts a terminalring element 24 to which it is secured in electrical contact by means ofsuitable countersunk bolts such as 25, the terminal ring element 24being insulated from the shaft l I and 1 and 2. A conducting extensionelement 44 extending downwardly from the terminal ring element 24 aspart of the latter, establishes electric connection between the sleeveconductor i2 and the terminal extension 4| of the upper end of theinducing coil l3, the terminal'extension 4| being threaded into theconducting extension 44. The terminal extension 42 is threaded into themanifold member 45 in electrical contact therewith, so that electricalconnection is established between the lower terminal extension 42 andthe tool shaft H, through the manifold member 45 and the tubular supportl9. The purpose of the manifold 45 is to effect an even distribution ofthe quenching fluid from the interior of the hollow supporting elementI9 to the spray nozzle. The manifold 45 is held in position on the endof the tubular mounting element l9 by means of the shoulder on theretaining head 29 and the abutting relation between the shoulder 46within the manifold member and the lower end of the tubular support 19.

The nozzle structure comprises an intermediate nozzle section 41.mounted about the manifold element 45 and provided with an abutment ringportion 53 arranged to be clamped upwardly the tubular mounting elementi9 by the intervening bushing element 26 of insulating material. Thering element 24 is provided with a downward, tubular extension 21 aboutwhich is carried an annular mounting flange element 28 insulated fromthe terminal ring element 24 and its tubular extension by a bushing 29of insulating material and mechanically secured to the ring element 2tby suitable countersunk bolts such as 36 insulated from the ring element24 by an insulating bushing 3|.

Threaded into the lower end of the mounting flange 28is a hollowcylindrical core support 32, carrying at its-lower end an otuwardlyextending, core-mounting flange 34; Between this flange and a clampingring 35 are clamped in place about the core support 32 a series of in--wardly tapered radial laminations 36 arranged in close contact to formthe hollow cylindrical core element l4, the clamping ring 35 being heldin clamping engagement with the top end of the laminations by a suitableclamping nut 37 threaded on to core support 32. a

The coil element l3 composed of one or more convolutions of a hollowconductor is wound about the laminated core 36 in the recessed portionbetween the upper and lower flanges l5 and I6, suitable insulation 38being provided between the convolutions of the coil and between the coiland the core. The upper and lower terminals of the (3011 are providedwith terminal elements 39 and 40, respectively, which connect withterminal extensions 4! and 42, respectively, extending inwardly throughthe hollow core i4 and insu lated from the latter by means of asector-shaped insulating plug 43 of the same contour in vertical sectionas the laminations so as to take the place of the laminationswhere theterminal extensions pass through the core, as will be clear from Figs.

against the lower end face of the flange 34 on the core support 32through the intermediation of an adjusting shim or shims 48 and theintervening, inwardly extending flange of a thin spun metal liningelement 49 covering the lower surfaces of an annular recess 50 in thelower core flange l6. Also mounted about the manifold element 45 belowthe intermediate nozzle section 41 is a bottom nozzle ring 5|, providedwith an abutment ring portion 52 arranged to be clamped against thebottom surface of the abutment ring 53 oithe intermediate sectionthrough the intermediation of an adjusting shim or shims 54. Thisclamping of the nozzle sections against each other and against thebottom of the tubular mounting element I9 is efiected by means ofsuitable countersunk cap screws such asthe cap screw 55 threaded intothe lower end of the tubular core support 32.

Quenching fluid is supplied to the nozzle from a suitable source ofsupply through the channel within the hollow tool shaft ii and thetubular supporting element Hi to the interior of the hollow retaininghead 2! in which the fluid is distributed through ports 26 in theretaining head and ports 51 in the manifold distributing element 45 tothe distributing chamber 58 in the nozzle structure, from which thequenching fluid is ejected downwardly and slightly outwardly of thenozzle through the restricted annular openings l I and 8. The quenchingfluid sprayed through the channel in the tubular supporting element i9also acts as a coolant for the inducingcoil i3 to which it is suppliedthrough a port 59 in the wall of the supporting tube element It and theand out through the bottom of the nozzle by way of outlet ports, one ofwhich is shown at ti and of which there may be several spaced around theinner portion of the nozzle between the ports 5'1. It is to beunderstood, of course, that the quenching and cooling fluid will besupplied at such a volume and pressure that the back pressure built upin the chamber 58 due to the restricted flow substantially constant is aprogressively movable bulkhead element in the form of the bulkheadpiston 13, as shown in Fig. 3. This piston is arranged to be moved upinto the cylindrical workpiece 6| in trailing relation to theheattreating head by means of a. hollow piston rod H, slidable through asuitable work cylinder 15 within which it is secured to a driving piston16 for imparting reciprocatory movement to the .rod for moving thebulkhead piston into and out of the workpiece. The flared form of theend member I2 at the bottom of the work holder aids in directing thebulkhead piston 13 into the lower end of the workpiece without injury tothe piston cap H. To insure maintenance of a'glven axial spacing betweenthe piston bulkhead and the bottom or nozzle portion of theheat-treating head, I provide a spacing element 18 carried by thebulkhead piston and arranged to abut the lower end of the heat-treatinghead. To permit drainage of the quenching liquid out of the spacebetween the heat-treating head and the bulkhead piston down through thehollow piston rod, the

spacing element 18 is given the form of an elon-.

gated open cage, as shown in Fig. 3. Thus, the extent of the zone ofcontact of the quenching fluid with the workpiece is maintainedsubstantially constant as the heating and quenching zones are progressedthrough the workpiece, the

waste quenching fluid being maintained isolated from other parts of theworkpiece during its passage out of the quenching zone.

A further improved feature of the present heattreating head is thesubstantial symmetrical relation of the path of inducing current to theworkpiece accomplished through the novel construction of the coilelement I3 whereby the end convolutions of the coil are made to lie inaplane at right angles to the axis for substantially a completeconvolution which results in the production of a heated zone in theworkpiece terminating axially in planes at substantially right angles tothe axis of the .0011. This is of special utility in combination withthe circular quenchand at the same time, because of their pressure andvelocity, permit the existence of some pressure within the quenchingchamber between the nozzle and the bulkhead piston, should it seemdesirable, which condition may be brought about by-suitable regulationof the drain and input to maintain the desired pressure, the velocity ofthe jets being maintained sufficient to prevent a backing up of thequenching fluid past the heat-treating head. With the structure shownand described the surface being quenched is thus made part of the wallof a channel filled on substantially filled with thecooling fluid orliquid flowing at high speed and, if desired, under high pressure, asdistinguished from the usual situation where the cooling fluid issplashed or sprayed agains the surface being cooled.

By arrangement of'the upper nozzle channel l1 within the lower flange orpole piece It to form an annular jet issuing substantially directly fromthe outer lower edge of the lower pole piece IS, the zone of initialcontact of the quenching fluid with the workpiece is brought intoextremely close proximity to the trailing end of the heated zone whichis the hottest portion of the heated zone. It is further to be pointedoutthat an advantage of the arrangement whereby cooling fluid isdirected through the hollow conductor of the coil l3 from bottom to top,that is in the direction of the progression of travel of the coilrelative to the workpiece, is that the part of the I coil which ispresented to the hottest portion of the progressing heated zone is firstto receive the cooling fluid. Also, because. the coil is intended totravel upwardly through the workpiece with the result that it is thelower terminal of the coil which is presented to the hottest part of theheated zone, thi terminal is the one selected for connection with thetool shaft H, which latter together with the workpiece, duringoperation,

will lie in electrical contact with a suitable support or frame elementnot shown, whereby that portion of the coil presented to they hottestpart of the work where arcing would ordinarily most likely occur, ismaintained at substantially the same potential as the workpiece.

In the use of the apparatus above described, for carrying out apreferred method of heat treatment, it being assumed that the tool shaftH and work holder are mounted for. relative axial and rotaryv motion inany known or other suitable manner which, for example, may be like thatshown in the aforesaid prior application, the tool shaft II is moveddownwardly to pass the heat-treating head 10 down through the workpieceGl to a position just below the lower end of the workpiece where theheat-treating head will be surrounded by the lower, low-reluctanceextension element 12. In this position, the inducing 'coil of theheat-treating head is energized from a suitable source of high frequencycurrent supplied to the coil by way of the tool shaft II and insulatedsleeve l2 through means of suitable contact brush elements which may beof any known or other suitable form, for example, that shown in theaforesaid application. The path of the energizing current may be tracedfrom the tool shaft ll, through tubular supporting element l9, terminalextension 42, terminal element 40, lower end of inducing coil I3,through the inducing coil to the upper terminal element 39, terminalextension ll, conducting extension ,conducting flange 24, back to thesource by way of the insulated conducting sleeve l2.

Immediately upon energization of the inducing coil, the heat-treatinghead is moved upwardly and out of the top end of the workpiecepreferably at a uniform rate of'-travel, the energizing current beingcut off after the inducing coil passes upwardly out of operativerelation with theworkpiece. Preferably, the energizing current is cutoff before the inducing coil leaves the upper low reluctance extensionelement, so as to prevent complete removal of the coil from thesurrounding medium of low reluctance and consequently prevent suddenreduction of the inductive reactance of the coil element. Thus, in

known manner, heating currents are generated in the workpiece occupyinga field in proximity to the heat-treating head which field of currentoccupancyand the resulting heated zone is progressed upwardly throughthe workpiece with the upward movement of the heat-treating head, thetrailing end of the heated zone being the hottest at any one moment dueto its. relatively longer exposure to the influence of the heattreatinghead.

Also upon energization of the inducing coil or slightly in advancethereof cooling and quenching fluid is forced down through the hollowtool shaft II and hollow supporting elementv is from any suitable sourceof supply, not shown. The cooling fluid thus forced downwardly throughthe hollow supporting element through lateral ports 56 in the hollowretaining head 2| and distributing ports 51 in the manifold element 45into the nozzle chamber 58 and out through the circular nozzle openingsl6 and I8 from whence it is forced downwardly and outwardly in twocontinuous curtains of fluid. Back pressure, developed due to therestricted flow through the nozzle openings, causes the cooling fluidalso to flow upwardly through the inducing coil by way of port 59 in thewall of the tubular supporting element l9 near the lower end, and thecentral channels in the terminal extension 42 and terminal element to,leaving the coil through the central channels of the terminal element 39and extension 4! from whence the cooling fluid flows downwardly and outthrough the bottom of the nozzle by way of drain ports, one of which isshown at 6| (Fig. 2).

Immediately, the lower peripheral edge of the core extension [6 reachesthe loweredge of the workpiece, at which moment the lower end of i9,passes on the workpiece is about at its highest temperature,

the jet of cooling-fluid issuing from the upper nozzle opening I!contacts with said portion of the workpiece to immediately initiate thequenching of the latter. This quenching of the inner surface of theworkpiece continues as the heattreating head moves upwardly, thequenching effect of the jet from the nozzle opening I1 being augmentedby that from the opening l8. Asthe heat-treating head moves upwardlythrough the' work, it is followed by the bulkheadpiston element 13 whoseentrance into the workpiece is guided by the outwardly flared lower endexten sion 12 in the work holder, the bulkhead piston being maintained adefinite distance below the heat-treating head by abutment of thespacing element 16 against the bottom of the heat-treating head. Thus,-the axial length of the quenching zone is maintained. at a givenmaximum. This progressive quenching operation is continued until andafter the heat-treating head has passed beyond the upper end of theworkpiece anduntil after the bulkhead piston reaches the top of theworkpiece and energizing current has been turned off. Concurrently withthe quenching operation the excess quenching fluid passes downwardlythrough the open spacing element 18 and the hollow piston rod 14 to asuitable .waste or drain connection, not shown. Also, as previouslydescribed, the jets of quenching fluid especially the uppermost jet,because of its downward direction and high velocity operates to preventquenching fluid from passing upwardly around the heattreating head, andeven may be maintained with suflicient pressure and velocity to permitthe existence of some pressure within the quenching chamber between thenozzle and the bulkhead.

piston. .High pressureis desirable not only because it increases therate of interchange of quenching fluid in contact with the surface beingquenched, but also increases the heat absorbing qualities of thequenching fluid.

It is to be understood that in the use of the invention hereindisclosed, either the heat-treating element or the workpiece, or bothmay be moved to efl'ect the required relative movement between them, andthat the mere mechanical inversion necessary to change from one suchform of relative movement to the other falls within the spirit of theinvention and is intended to be covered by those of the appended claimsspecifying either of such forms of movement, in accordance with thedoctrine of equivalents.

- While I have thus herein shown and described a specific embodiment anduseful application of my invention for the sake of disclosure, it is tobe understood that the invention is not limited to such specificembodiment and mode of application, but contemplates all such variantsand modifications thereof as fall fairly within the scope of theappended claims.

What is claimed is:

1. In combination an induction heat-treating head comprising a hollowcylindrical core support, a hollow cylindrical radially laminated coremounted on said support, a flange carried by thesupport near thelongitudinally outer end for engagement with the longitudinally outerend of the core, a clamping nut threaded onto the support longitudinallyinward of the core for clamping the core against the said flange, a.tubular conductor winding for the core having terminals extendingradially inward to the interior of the support, a mounting flangethreaded onto the longitudinally inner end of the core support, aterminal ring element secured to the mounting flange and insulatedtherefrom, a conducting extension element connecting the terminal ringwith the longitudinally inner terminal of the tubular winding throughthe interior of the support, a hollow supporting shaft for the coil andcore support extending through the core support and electricallyconnected with the longitudinal member, an inducing coil surroundingsaid memher, said member having an opening through the cylindrical wallthereof and said coil having terminal ends extending through saidopening to the interior of said member, an electrically conductivemandrel separate from and disposed within said member and beingelectrically connected with one of said terminal ends, an electricallyconductive member surrounding and elecfrom, a tubular coil supportcarried by said annular member in surrounding relation with respect tosaid mandrel, an inducing coil carried by said support, said coil havingterminal ends extendingthrough the wall of said support, one of saidterminal ends being electrically connected with said mandrel, and meanswithin said support electrically connecting said sleeve with the otherof said coil ends.

4. In an induction heat-treating head having a central electricallyconductive mandrel, an electrically conductive sleeve surrounding saidmandrel, a sleeve of insulating material between said sleeve and mandreland being axially slidable relative to one of said sleeve and mandrel,tubular means connected with said sleeve and surrounding said mandrel incircumferentially spaced relation, an inducing coil carried by saidtubular means and having terminal ends extending through the wallthereof, one of said terminal ends being electrically connected withsaid sleeve and the other of said terminal ends having an axiallyslidable electrical connection with said mandrel, said sleeve, tubularmeans and coil including said terminal ends being axially movable as aunitary assembly for assembly to and disassembly from said mandrel, andremovable means for holding said unitary assembly on'said mandrel.

5. In an induction heat-treating head, a pair of spaced coaxial tubularconductors, means insulating said conductors from each other, aninducing coil having one of its terminal ends electrically connectedwith one of said conductors and the other of its terminal ends connected6. In an induction heat-treating head, a pair of spaced coaxial tubularconductors, means insulating said conductors from each other, an

inducing coil having one of its terminal ends electrically connectedwith one of said conductors and the other of, its terminal endsconnected with the other of said conductors, and a supporting arbor, oneof said conductors-being rigidly secured to said arbor in electricalcontact therewith and the other of said tubular conductors being insurrounding relation with respect to said arbor and being electricallyinsulated therefrom, said inducing coil being hollow to conduct coolingfluid therethrough and said arbor and saidone conductor havingcommunicating fluid passages. in communication with the interior of saidcoil to conduct cooling fluid to said coil.

7. In an induction heat-treating head, a tubular member of electricallyconductive material, means surrounding said tubular member incircumferentially spaced relation and forming a chamber therewith, aninducing coil surrounding said means and having end terminals at leastone of which extends radially through the wall of said means, anelectrically conductive sleeve surrounding at least a portion of thebody and end of said tubular member in electrical contact therewith andhaving an electrical connection with said one terminal, and means forclamping said sleeve to said tubular member.

8. In an induction heat-treating head, a tubular member of electricallyconductive material, means surrounding said tubular member incircumferentially spaced relation and forming a chamber therewith, aninducing coil surrounding said means and having end terminals at leastone of which extends radially through the wall of said means, anelectrically conductive sleeve surrounding at least a portion of thebody and end of said tubular member in electrical contact therewith andhaving an electrical connection with said one terminal, and means forclamping said sleeve to said tubular member, said coil havingapassageway therethrough communicating through said one connection withthe interior of said tubular member for receiving cooling fluidtherefrom and communicating through the other of its terminals with saidchamber to discharge cooling fiuid thereinto.

9. In an induction heat-treating head, a tubular member of electricallyconductive material, means surrounding said tubular member incircumferentially spaced relation and forming a chamber therewith, aninducing coil surrounding said means and having end terminals at leastone of which extends radially through the wall of said means, anelectrically conductive sleeve surrounding the end of said tubularmember in electrical contact therewith and having an electricalconnection with said one terminal, and means for clamping said sleeve tosaid tubular member, said head including a tubular conductor surroundingand insulated from said tubular of its longitudinal increments uniformlycircum ferentially spaced from such surface with substantially minimumclearance, said trailing end beingof suflicie'ntly less diameter thansaid leading end to substantially maintain said uniform,

circumferential clearance upon expansion of the portion of thecircumferential surface adjacent said trailing endwhen heated.

11. An induction heating head for longitudinally progressively heating acircumferential surface of an elongated cylindrical article throughoutthe circumferential extent thereof, comprising a heating coil and a coreof magnetic material therefor, said core having coaxial cylindrical endportions extending radially across the ends of said coil,'one of saidportions constituting a leading end and the other portion constituting atrailing end, said heating head being arranged to be positioned adjacentthe circumferential surface to be heated with eachlongitudinal-increment of each of said end' portions arranged to have asubstantially minimum, uniformly circumferential clearance with suchsurface, said trailing end portion Leing of less diameter than saidleading end to compensate for expansion toward the same of thecircumferential surface to be heated, the respective ends of said coiladjacent said end portions being of no greater diameter than said end Iportions.

v 1y outermost edge of said leading end portion to 10 the axiallyoutermost edge of said trailing edge portion to effect a clearance withthe circumferential surface to be heated greater at said trailing endthan at said leading end whereby'to compensate for expansion of thecircumferential surface undergoing heating toward said end por tions,said coil being arranged to have a clearancewith such suriace at leastas great as said end portions. v

' HOWARD'E. SOMES.

